HP 2500 Service Manual - Page 64

Basic sequence of operation Operation sequences are controlled by the CPU in the dc controller in the engine control system. Table describes engine operations for each period of a print operation. Table 15. Basic sequence of operation Period Duration Purpose Remarks WAIT (wait) From the time the power switch is turned on until transfer-belt cleaning is complete. Clears potential from the See figure 12 for a complete drum surface and cleans the description of the WAIT transfer belt. (power-on) period. Also see the general timing charts beginning on page 212 for detailed information about timing. STBY (standby) From the end of the WAIT or Allows the printer to be LSTR period until either a ready for print commands. print command is sent from the formatter or the power is turned off. INTR (initial rotation) From the time of the print Prepares the photosensitive command until detection of drum for printing. the HP1 (transfer-belt homeposition detection) signal for the first color. PRINT (print) From the end of the INTR period until detection of the transfer-belt home-position signal for the secondary transfer. Forms the image on the photosensitive drum and transfers the toner image to the transfer belt. LSTR (last rotation) From the end of the PRINT period until the main motor stops rotating. Transfers the toner image on After LSTR, the printer the transfer belt to the media returns to STBY. and delivers the printed media. 62 Theory of operation C9706-90926